1 // Copyright (c) 2020 Vasyl Teliman
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "source/fuzz/fuzzer_pass_mutate_pointers.h"
16
17 #include "source/fuzz/fuzzer_context.h"
18 #include "source/fuzz/fuzzer_util.h"
19 #include "source/fuzz/transformation_mutate_pointer.h"
20
21 namespace spvtools {
22 namespace fuzz {
23
FuzzerPassMutatePointers(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations,bool ignore_inapplicable_transformations)24 FuzzerPassMutatePointers::FuzzerPassMutatePointers(
25 opt::IRContext* ir_context, TransformationContext* transformation_context,
26 FuzzerContext* fuzzer_context,
27 protobufs::TransformationSequence* transformations,
28 bool ignore_inapplicable_transformations)
29 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
30 transformations, ignore_inapplicable_transformations) {}
31
Apply()32 void FuzzerPassMutatePointers::Apply() {
33 ForEachInstructionWithInstructionDescriptor(
34 [this](opt::Function* function, opt::BasicBlock* block,
35 opt::BasicBlock::iterator inst_it,
36 const protobufs::InstructionDescriptor& instruction_descriptor) {
37 if (!GetFuzzerContext()->ChoosePercentage(
38 GetFuzzerContext()->GetChanceOfMutatingPointer())) {
39 return;
40 }
41
42 if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpLoad, inst_it)) {
43 return;
44 }
45
46 auto available_pointers = FindAvailableInstructions(
47 function, block, inst_it,
48 [](opt::IRContext* ir_context, opt::Instruction* inst) {
49 return TransformationMutatePointer::IsValidPointerInstruction(
50 ir_context, *inst);
51 });
52
53 if (available_pointers.empty()) {
54 return;
55 }
56
57 const auto* pointer_inst =
58 available_pointers[GetFuzzerContext()->RandomIndex(
59 available_pointers)];
60
61 // Make sure there is an irrelevant constant in the module.
62 FindOrCreateZeroConstant(fuzzerutil::GetPointeeTypeIdFromPointerType(
63 GetIRContext(), pointer_inst->type_id()),
64 true);
65
66 ApplyTransformation(TransformationMutatePointer(
67 pointer_inst->result_id(), GetFuzzerContext()->GetFreshId(),
68 instruction_descriptor));
69 });
70 }
71
72 } // namespace fuzz
73 } // namespace spvtools
74